PYLON CONVERSION ACTUATOR FOR TILTROTOR AIRCRAFT
A pylon conversion actuator, for use in tiltrotor aircraft, that converts the tiltrotor between hover flight mode and forward flight mode. Pylon conversion actuator selectively retracts and extends between a retracted position to an extended position. Pylon conversion actuator includes an extendable arm, a motor, and an actuator platform.
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The present disclosure relates, in general, to tiltrotor aircraft that have a hover flight mode and a forward flight mode and, in particular to an improved pylon conversion system optimized for use on a tiltrotor aircraft.
BACKGROUNDAn example of an aircraft is a tiltrotor aircraft. A tiltrotor aircraft generally has a rotor system that can selectively rotate relative to a body and wings. A tiltrotor aircraft can operate in a hover flight mode by vertically orienting its rotor systems into an upright position. In hover flight mode, the tiltrotor aircraft generates a lifting force by rotating a plurality of rotor blades, which allows the tiltrotor aircraft to make vertical takeoffs or vertical landings with little or no forward momentum. The tiltrotor aircraft can also operate in a forward flight mode by horizontally orienting its rotor systems in a forward position. In forward flight mode, the tiltrotor aircraft generates a lifting force by running an airflow over an aerodynamic wing surface, which allows the tiltrotor aircraft to reach a greater forward airspeed than would otherwise be possible in hover flight mode.
Some tiltrotor aircraft have a propulsion assembly comprising a fixed pylon system and a rotor system. A pylon conversion actuator mounted to the fixed pylon system can rotate the rotor system between an upright position and a forward position.
For a more complete understanding of the features and advantages of the present disclosure, reference is now made to the detailed description along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative and do not delimit the scope of the present disclosure. In the interest of clarity, not all features of an actual implementation can be described in the present disclosure. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
In the specification, reference can be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices, members, apparatuses, and the like described herein can be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein can be oriented in any desired direction. In addition, as used herein, the term “coupled” can include direct or indirect coupling by any means, including moving and/or non-moving mechanical connections.
Referring to
The pylon conversion actuator 106 includes an extendable arm 120, an actuator platform 118, and a primary power source 116. The primary power source 116 is mounted to the top of the actuator platform 118, which in turn is fixed proximate to the upper end of the extendable arm 120. In certain embodiments, the primary power source 116 is a hydraulic motor; but the primary power source 116 can include multiple motors, different motor types, batteries, generators, and other suitable devices. Additionally, the pylon conversion actuator 106 can include one or more redundant power sources 122 mounted to the bottom structure of the pylon conversion actuator 106. In certain embodiments, the redundant power source 122 is a hydraulic motor; but the redundant power source 122 can include multiple motors, different motor types, batteries, generators, and other suitable devices. The primary power source 116 is used to power and move the extendable arm 120. If the primary power source 116 fails, the redundant power source 122 can power and move the extendable arm 120. The extendable arm 120 can selectively retract into a retracted position, as best seen in
The pylon conversion actuator 106 is directly mounted to the rotor system 24a and the fixed pylon 22a by a gimbal mount 110 and clevis mount 112 respectively. The gimbal mount 110 is below and forward of the clevis mount 112. As a result, the pylon conversion actuator 106 mounts to the rotor system 24a and fixed pylon 22a at an angle 130.
The gimbal mount 110 is fixed to the pylon assembly 22a by a pair of pylon tangs 108, located along the leading forward edge of the fixed pylon 22a. An aperture opening extends through a central body of the gimbal mount 110. The pylon conversion actuator's 106 extendable arm 120 extends through the gimbal mount's 110 aperture opening, where it is secured in place by the gimbal mount 110. In both the retracted position and the extended position, the actuator platform 118 is situated above the gimbal mount 110; and, the actuator platform 118 is restricted from physically touching the gimbal mount 110. Additionally, the gimbal mount 110 allows the pylon conversion actuator 106 to selectively move within the confines of the aperture opening in a side-to-side motion and/or a forward to aft motion; however, the gimbal mount restricts the pylon conversion actuator 106 from moving in an up or down direction and absorbs tension and compression loads generated by the pylon conversion actuator 106.
The clevis mount 112 is fixed to the side surface of the rotor system 24a. The clevis mount 112 includes a pair of clevis tangs. The upper end of the pylon conversion actuator 106, proximate to the primary power source 116 and actuator platform 118, is situated between the clevis tangs and fastened to the rotor system 24a by a clevis joint 114. The clevis mount 112 allows the pylon conversion actuator 106 to selectively pivot about the clevis joint 114. As the extendable arm 120 of the pylon conversion actuator 106 retracts and extends, the pylon conversion actuator 106 will respectively pull and push on the clevis mount 112 and pivot the rotor system 24a about the conversion axis 104. As a result, when the extendable arm 120 retracts into the retracted position, the rotor system 24a rotates into the forward position, as best seen in
Referring to
At least one embodiment is disclosed, and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of this disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of this disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, Rl, and an upper limit, Ru, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=Rl+k*(Ru−Rl), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 95 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed.
Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. Also, the phrases “at least one of A, B, and C” and “A and/or B and/or C” should each be interpreted to include only A, only B, only C, or any combination of A, B, and C.
Claims
1. A propulsion system for a tiltrotor aircraft having a wing, the tiltrotor aircraft operable in a hover flight mode and a forward flight mode, the propulsion system comprising:
- a fixed pylon;
- a rotor system comprising a rotor system central axis;
- a pivotable attachment coupling the rotor system to the fixed pylon, the pivotable attachment comprising a conversion axis, wherein the rotor system is configured to selectively rotate about the conversion axis;
- a pylon conversion actuator comprising; a first actuator mount directly coupled to the fixed pylon; a second actuator mount directly coupled to the rotor system; and an extendable arm coupled to the first actuator mount and the second actuator mount and actuatable between an extended position and a retracted position;
- wherein in the extended position, the pylon conversion actuator places the rotor system in a first rotor position; and
- wherein in the retracted position, the pylon conversion actuator places the rotor system in a second rotor position.
2. The propulsion system of claim 1, wherein the second actuator mount is situated above the first actuator mount.
3. The propulsion system of claim 2, wherein the first actuator mount and second actuator mount are oriented on a vertical axis that is approximately perpendicular with the wing.
4. The propulsion system of claim 1, wherein the first actuator mount and the second actuator mount couple the pylon conversion actuator to the fixed pylon and rotor system at an angle.
5. The propulsion system of claim 1, wherein:
- in the hover flight mode, the rotor system is in the first rotor position; and
- in the forward flight mode, the rotor system is in the second rotor position.
6. The propulsion system of claim 5, wherein the rotor system rests on a rotor downstop in the second rotor position.
7. The propulsion system of claim 1, wherein the first actuator mount is configured to selectively translate the pylon conversion actuator in a side-to-side motion and a forward and aft motion.
8. The propulsion system of claim 7, wherein the first actuator mount comprises a gimbal mount.
9. The propulsion system of claim 1, wherein the second actuator mount is configured to selectively pivot the pylon conversion actuator.
10. The propulsion system of claim 9, wherein the second actuator mount comprises a clevis mount.
11. The propulsion system of claim 1 further comprising a redundant power source to power the pylon conversion actuator.
12. The propulsion system of claim 1, wherein the pylon conversion actuator is offset from the pylon central axis.
13. The propulsion system of claim 12, wherein the pylon conversion actuator is offset from the pylon central axis towards an outboard end of the wing.
14. The propulsion system of claim 13, wherein the rotor system further comprises a protruding mount structure configured to directly coupled with the second actuator mount.
15. The propulsion system of claim 1, wherein the extendable arm is a segmented telescoping bar.
16. A method of using an instrument system in communication with a pylon conversion actuator for a tiltrotor aircraft, wherein the pylon conversion actuator is directly mounted to a rotor system and directly mounted to a fixed pylon, wherein the pylon conversion actuator has an extended position and a retracted position, the method comprising:
- receiving a signal from an instrument system;
- determining whether the pylon conversion actuator is in an extended position or a retracted position;
- sending a command to the pylon conversion actuator to retract to the retracted position if the pylon conversion actuator is in the extended position; and
- sending a command to the pylon conversion actuator to extend to the extended position if the pylon conversion actuator is in the retracted position.
17. The method of claim 16 further comprising:
- placing the rotor system into a first rotor position by extending the pylon conversion actuator into the extended position; and
- placing the rotor system into a second rotor position by retracting the pylon conversion actuator into the retracted position.
18. The method of claim 17 wherein:
- the first rotor position is an upright position; and
- the second rotor position is a forward position.
19. A tiltrotor aircraft, the aircraft comprising:
- a fuselage body;
- a wing;
- a first rotor system coupled to the wing comprising: a first fixed pylon; a first rotor system; a first pivotable attachment coupling the first rotor system to the first fixed pylon comprising a first conversion axis, wherein the first rotor system is configured to selectively rotate about the first conversion axis;
- a first pylon conversion actuator comprising; a first lower actuator mount directly coupled to the first fixed pylon; a first upper actuator mount directly coupled to the first rotor system; and a first extendable arm coupled to the first lower actuator mount and the first upper actuator mount and actuatable between a first extended position and a first retracted position;
- wherein in the first extended position, the first pylon conversion actuator places the first rotor system in a first upright position; and
- wherein in the first retracted position, the first pylon conversion actuator places the first rotor system in a first forward position.
20. The tiltrotor aircraft of claim 19 further comprising:
- a second rotor system coupled to the wing symmetrically aligned with the first rotor system about the fuselage body comprising: a second fixed pylon; a second rotor system; a second pivotable attachment coupling the second rotor system to the second fixed pylon comprising a second conversion axis, wherein the second rotor system is configured to selectively rotate about the second conversion axis; a second pylon conversion actuator comprising; a second lower actuator mount directly coupled the second fixed pylon; a second upper actuator mount directly coupled to the second rotor system; and a second extendable arm coupled to the second lower actuator mount and the second upper actuator mount and actuatable between a second extended position and a second retracted position;
- wherein in the second extended position, the second pylon conversion actuator places the second rotor system in a second upright position; and
- wherein in the second retracted position, the second pylon conversion actuator places the second rotor system in a second forward position.
Type: Application
Filed: Dec 11, 2020
Publication Date: Jun 16, 2022
Patent Grant number: 11745867
Applicant: Bell Textron Inc. (Fort Worth, TX)
Inventors: William ATKINS (Carrollton, TX), George Ryan DECKER (Loveland, CO), Steven Allen ROBEDEAU, JR. (Keller, TX)
Application Number: 17/119,703